Fab 3" square tubing quesion

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I need to notch the end of a few pieces of 3" square 1/8" wall alum tubing to mate up with the wall of 5" sched 40 alum pipe.So far I've used my 4x6 Grizzly bandsaw but the blade is too wide to get a nice profile. I disconnected the hydraulic feed control and stood it up like a vert saw but only had the edge of the roller guide to use as a table. Then I used a flap disk that I use for just alum. I also tried my Delta 4x36 belt sander to smooth out the curve.Overall I've spent a bunch of time just to end up with a sloppy fit up. Any ideas for a guy with limited tools?How do you know the blacksmith's dog? When you hollar at him he makes a bolt for the door!
Reply:What about a holesaw -http://www.ridgid.com/tools/5-bi-met...w/en/index.htmMike
Reply:Jig saw?Millermatic 252millermatic 175miller 300 Thunderboltlincoln ranger 250smith torcheslots of bfh'sIf it dont fit get a bigger hammer
Reply:I got them done with the band saw and flap disk.I couldn't get a 5" hole saw to work on a 3" surface (because I don't have a 5" hole saw ) and I couldn't get my jig saw to cut the full depth from one edge to another 3" apart without stabbing the krap out of the inside of the far edge of the tube.I ended up welding the poor fit up and using 2 18" rods of 3/32" filler for each of the 3" legs of weld 4 pcs of 3" tube mated up to 5" sched 40 pipe used (4pcs x 4 sides x 2 tig rods) 32 pcs of 18" filler. It sorta looks like the butkrack of dawn just got welded lol.Not that it matters but they held water All good though, it's done. Thanx guys.How do you know the blacksmith's dog? When you hollar at him he makes a bolt for the door!
Reply:I know you are already done but one way is to lay it out with a compass while the 3" is still a full length then cut your lines with what ever you have.Do not argue with an idiot. He will drag you down to his level and beat you with experience.
Reply:i find my bandsaw to be of very limited use. if i had a bundle of  rod or lengths of watever it is the perfect tool to set up a cut and walk away. anything intricate it is way too much trouble..go to handheld tool  like a thinwheel on a 4"grinder(careful) or a portaband..or a hacksaw...
Reply:I know you're done but next time try the hole saw set up in a drill press.  Cat's meow.
Reply:Drum sander or the end of a belt sander?    5" grinding wheel using the edge of the wheel?   DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:on handrail in the incline i use a 2in  soild cone sander for inside bushings,works very good.if your tube is 3?16  a 00 cuting  tip and torch can give some good results,if your not too shakey.
Reply:neckless,I imagine most anyone would be a little shaky, cutting 1/8" aluminum tube with a torch.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Next time beg, borrow or steal.........for a day anyway, a plasma cutter.Lincoln Power Mig 216Lincoln AC/DC-225/125Miller  625 X-Treme PlasmaMiller 211 Forney 95FI-A 301HF 91110Victor Journeyman O/PMilwaukee DaytonMakita  Baileigh NRA Life Member
Reply:A plasma cutter?  Really?Have you cut much 1/8" aluminum with a plasma cutter?Cutting aluminum with a plasma cutter means a good deal of grinding to remove the oxides created by plasma cutting, before the part can be welded.This really is a very easy joint to prep.In the absense of a 5" holesaw and an aluminum dedicated drill press, this is how I'd prep it.Mark your position all the way around the tube using a square.Cut the two vertical walls with the bandsaw  (I use a standard Delta woodcutting bandsaw (6 tpi blade) dedicated to aluminum)Cut a 5" disk (pattern) out of cardboard, 1/4" plywood, whetever.  Use this to mark the top and bottom member of the tube.Make the circumference cuts with a jig saw and small blade (I use the Bosch with a very narrow blade).  1/8" aluminum cuts like butter with the jigsaw, just let the blade do the work.Saw cutting the tube results in the tube being "ready for welding", vs the cleanup you'd have to do if plasma was used.Funny how everyone seems to think that plasma cutters are the "end all" when it comes to cutting metal.  Not true.  Some of the "old ways" still work better.With the tools in the shop right now (dedicated aluminum bandsaw, drill press, and 5" holesaw), each of these parts could be prepped (cut) in about 5 min.Cutting the tube square with your horizontal bandsaw and "notching the circumference cuts) with the jigsaw will also work well.Last edited by SundownIII; 04-26-2012 at 12:54 PM.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Thanks guys and Sundown.I considered using the jigsaw but didn't think I'd be successful with it. Turns out it would've probably been much easier. I have a small bench top Delta drill press that has some run out (wobble) but don't have a hole saw larger than 3".Just glad it didn't require 20 or so of 'em or I would've had brain damage making it harder if I didn't buy the right tool to make the job easier.Anyhow for a rookie/hobbiest it's funny  how humbling trying to fab up something three dimensional can be. No matter how small.Next weekend I'll cut the grass with my string trimmer and cut the deck of my mower so I can turn it on it's side to edge/trim just to remind me how much easier life's tasks are when you do it logically with the right tools How do you know the blacksmith's dog? When you hollar at him he makes a bolt for the door!
Reply:There is nothing wrong with a palsma cut edge, I don't see the problem there, maybe I don't prep my welds right, but I plasma cut 1/8" alum all the time with very little prep before welding. What I do is get a 5" hole saw, replace the guide drill with a long rod.  the rod goes into a plate which a angle iron is welded on.  This way you can notch a moon shape cut out of each edge of the square and still leave full thickness sides.  Kind of like a hole saw tubing notcher but with a rod supporting the larger hole saw by running through the supporting plate. I know you said you don't have the saw or press, but plasma or hole saw is the only ideas I can think of. A jig saw as mentioned above would work fine for small runs as well.
Reply:Originally Posted by SundownIIIA plasma cutter?  Really?
Reply:SuperArc,You are so full of it.Over the last 30 years, I've cut and welded more aluminum than you can imagine.Since you don't even show a tig welder in your profile, and that's what the OP was using to fab his project, I wouldn't expect you to have a clue about the oxides created by cutting aluminum with a plasma cutter.I have both a Powermax 600 and a Powermax 1250 in my shop that are used all the time, but seldom on aluminum.I have a dedicated 14" Delta bandsaw used for aluminum.  A porta band, a Milwaukee Metal Cut saw with a 8" aluminum blade, and a Bosch jig saw all used for preping aluminum.If you'd EVER tried tig welding a plasma cut edge, you'd know what problems it creates.  With your squirt gun welders, you're just burying the oxides, creating a weak weld, and don't even know it.A jig saw with a quality blade cuts 1/8" aluminum like 1/4" plywood and has much more control than ANY plasma cutter.Ask any marine fabricator what he uses to cut aluminum and you'll find that plasma is way down the list (if on the list at all).If you're mig welding plasma cut aluminum, without removing the oxides (say with a die grinder) then you're compromising the strength of the weld by burying the oxides in the weld bead.  Tig welding (as the OP was doing) will prove it.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Sitting here LOL.In SuperArc's 5/3/10 post (where he questioned using a 120v mig welder for aluminum) he states "I've never mig welded aluminum before", and now he's a freaking EXPERT on prepping the stuff for welding.Besides all this, the OP clearly stated that he was limited in his availablilty of "basic fab tools" (vertical band saw, drill presses, hole saws, etc).  Why would SA think that he had a plasma cutter available.  On the other hand, many hobby welders (handymen) have a jig saw and can pickup a $3 blade.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Sundown.  Two words:1. Anger2. Management. You're hilarious.   Lincoln Power Mig 216Lincoln AC/DC-225/125Miller  625 X-Treme PlasmaMiller 211 Forney 95FI-A 301HF 91110Victor Journeyman O/PMilwaukee DaytonMakita  Baileigh NRA Life Member
Reply:You're right about one thing.I'm angry about posters blowing a bunch of smoke about things they know nothing about.One day, you're "just a hobby welder just learning" and the next day you're a freaking expert.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Calm down there Arch. Lincoln Power Mig 216Lincoln AC/DC-225/125Miller  625 X-Treme PlasmaMiller 211 Forney 95FI-A 301HF 91110Victor Journeyman O/PMilwaukee DaytonMakita  Baileigh NRA Life Member
Reply:Sundown.....just can't resist jumping in. On the contrary there are three major aluminum boat manufacturers in the US that cut virtually all of their aluminum with plasma......some use air plasma (the worst for edge contamination) and some use industrial high definition plasma with non oxidizing gases (methane/nitrogen and argon/ hydrogen as well as nitrogen/nitrogen for gases) which provides for a relatively weld ready edge.Aluminum edges do need preparation before tig welding.....but the time saved cutting....especially if the cuts are complex and require accuracy....is more than enough to offset the cleanup....at least in production operations. I would agree with you that for the occasional user that has to layout the part by hand (not using a cnc) maybe the saw is as productive. Here are some pics of parts that I have cut many of....the buyer of these parts chooses my plasma cut parts over both water jet and laser......because they are substantially lower priced.....because I cut these parts very fast on my cnc. The first part is .080" aluminum.....a tank baffle that gets welded. The second and third are seats for a zipline trolley, they are 3/16" and get a couple of welds.....have done thousands with no complaints about weldability...though I'm sure the parts are cleaned well first.Jim Colt  Originally Posted by SundownIIISuperArc,You are so full of it.Over the last 30 years, I've cut and welded more aluminum than you can imagine.Since you don't even show a tig welder in your profile, and that's what the OP was using to fab his project, I wouldn't expect you to have a clue about the oxides created by cutting aluminum with a plasma cutter.I have both a Powermax 600 and a Powermax 1250 in my shop that are used all the time, but seldom on aluminum.I have a dedicated 14" Delta bandsaw used for aluminum.  A porta band, a Milwaukee Metal Cut saw with a 8" aluminum blade, and a Bosch jig saw all used for preping aluminum.If you'd EVER tried tig welding a plasma cut edge, you'd know what problems it creates.  With your squirt gun welders, you're just burying the oxides, creating a weak weld, and don't even know it.A jig saw with a quality blade cuts 1/8" aluminum like 1/4" plywood and has much more control than ANY plasma cutter.Ask any marine fabricator what he uses to cut aluminum and you'll find that plasma is way down the list (if on the list at all).If you're mig welding plasma cut aluminum, without removing the oxides (say with a die grinder) then you're compromising the strength of the weld by burying the oxides in the weld bead.  Tig welding (as the OP was doing) will prove it.
Reply:Yeah, I don't know what the problem is. Seems like there's always "one" in a group that thinks he's always right and everyone else is wrong. Then he yells, screams and attacks members here that  view a different opinion than his own. Oh  well.  I just give an opinion and watch him come apart at the seams.  Makes great comedy at some loooong rants ive seen posted.  Recently, he even created a new user name and tried to "back up" himself in another thread.  Was funny! Kinda like sending a dozen roses to oneself at the office, wanting co workers to think someone is getting support.  Funny stuff. As far as plasma goes, I don't have a problem with cutting aluminum.  Yes I weld it with a spool gun (ohhhh those evil spool guns!).  Been doing so now for the past TWO years according to "Archie's" calculations.   (note to self: wow! Has it been that long already?)   Again, I can control my steady hand, grind off any slag and weld up. I'm not fabricating a 747 or a drone UAV....  I'm just having fun.... I also don't let my blood pressure go up from reading an Internet post.  Life ain't that serious!!!! Jim Colt..... Beautiful cut and finished aluminum pics there! Thanks for posting.Lincoln Power Mig 216Lincoln AC/DC-225/125Miller  625 X-Treme PlasmaMiller 211 Forney 95FI-A 301HF 91110Victor Journeyman O/PMilwaukee DaytonMakita  Baileigh NRA Life Member
Reply:Wow, I didn't know there were so many opinions.  All I know is I TIG and MIG aluminum after plasma cutting.  If there is oxides or slag, I do brush it before I weld , but I have not seen a problem.  Oxides will come up obviously when you tig weld.  If that happens brush and keep going.  I'm sure if you are doing a text book weld on a space shuttle project, there may be other considerations.  For most real world welding, normal cleaning, even with a carbon steel brush (if you don't have a dedicated stainless) seems plenty good enough for anything I have done.  Then again, I taught myself, but have been welding for 35 years.